[lkml]   [2006]   [Sep]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: GPLv3 Position Statement
    I generally agree with you, but...

    Linus Torvalds <> writes:

    > And it not at all uncommon to have a flash that simply cannot be upgraded
    > without opening the box. Even a lot of PC's have that: a lot (most?) PC's
    > have a flash that has a separate _hardware_ pin that says that it is
    > (possibly just partially) read-only. So in order to upgrade it, you'd
    > literally need to open the case up, set a jumper, and _then_ run the
    > program to reflash it.

    I think this is history. Yes, late 486s and Pentiums (60 and 66?)
    had a jumper protecting the flash. It's not true since ca. "Pentium 75+"
    days - while many boards use "bootblock" chips, it's (almost?) always
    unprotected (at most it just requires setting some GPIO pin(s)). The
    rest of flash obviously has to be R/W to support the ESCD etc.

    I think there are systems with 2 copies of the whole BIOS, and the
    user selects the copy with a jumper (probably connected directly to
    the most significant address line of the flash IC) - the second
    copy might theoretically use a R/O bootblock but I've never checked it.

    Most VGAs, disks, PCI cards etc. have flash chips with no protection
    either, and I have to say I felt much better when they used (EP)ROMs.

    I think almost all hardware manufacturers use a blank flash chips,
    programming them "in system" with things like JTAG.
    Krzysztof Halasa
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2006-09-27 22:37    [W:0.034 / U:40.868 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site